Kitsap County is a county located in the state of Washington. The county seat is at Port Orchard. Its largest city is Bremerton. It was named after Chief Kitsap of the Suquamish tribe. As of 2000, the population is 231,969. The United States Navy is of great importance to the county, with installations at Puget Sound Naval Shipyard, Naval Undersea Weapons Engineering Station, Keyport, and Naval Base Kitsap (which is comprised of former NSB Bangor and NS Bremerton).

Kitsap County is connected to the eastern shore of Puget Sound by Washington State Ferries runs from Bremerton to Downtown Seattle and from Southworth to West Seattle via Vashon Island. The county has a total area of 1,466 km˛ (566 mi˛). 1,026 km˛ (396 mi˛) of it is land and 440 km˛ (170 mi˛) of it is water. The total area is 30.04% water.

As of the census of 2000, there are 231,969 people, 86,416 households, and 61,355 families residing in the county. The population density is 226/km˛ (586/mi˛). There are 92,644 housing units at an average density of 90/km˛ (234/mi˛). The racial makeup of the county is 84.27% White, 2.87% Black or African American, 1.62% Native American, 4.39% Asian, 0.78% Pacific Islander, 1.43% from other races, and 4.64% from two or more races. 4.14% of the population are Hispanic or Latino of any race.

The median income for a household in the county is $46,840, and the median income for a family is $53,878. Males have a median income of $39,889 versus $28,586 for females. The per capita income for the county is $22,317. 8.80% of the population and 6.30% of families are below the poverty line. Out of the total population, 10.90% of those under the age of 18 and 6.00% of those 65 and older are living below the poverty line.